Batteries Definition and 464 Threads

Homework Statement Hi there, I just want to see if I am doing these questions correctly. Any help with this would be great. The question and circuit diagram are in the attachment. CheersHomework Equations Kirchoff's Laws for voltage and current. I'm not too sure if there is an equation, you...

Hello, I am designing a circuit that will be running off of two AA rechargeable (1.2V 2500mAH NiMH) batteries that are stacked in series, and I am looking into a way to charge the batteries in-circuit rather than having to take them out and charge them externally. I did a very brief search...

Dear Gurus, o:) I bought a pair of AAA nimh batteries rated at 1.2V 900mAh. Fast charge can be done in 5 hours @ 270mAh. Standard charge can be done in 15hours @ 90mA. My doubt is assuming both batteries have different impedence, can they be charged in Series at say between 1.4v to 1.6v using...

I'm a documentary filmmaker and I am trying to build battery powered china lantern using an 13w Evolux SH LED array light bulb (http://eartheasy.com/store/proddetail.php?prod=EvoLuxSH). I'd like to use something like D-Cell rechargable batteries, possibly from a modified light bulb, although...

I use TI-89 Titanium normally. It was not even a month since I changed my batteries. One day I pressed on but did not turn on. I tried out other batteries and found out that batteries were not the matter of problem. What's wrong? What should I do?

Homework Statement two batteries A and B are connected in parallel, and an 80 ohm resistor is connected across the battery terminals. the e.m.f and the internal resistance of battery A are 100V and 5ohms respectively, and the corresponding values for battery B are 95V and 3ohms respectively...

A quick google search reveals conflicting opinions on whether or not this will have a negative impact on battery life. I carry my laptop outdoors with me every day on my walk from the train to the hospital, do I need to worry about the cold ruining my battery?

Homework Statement In the figure, R1 = R2 = 2.0, R3 = 4.0, R4 = 3.0, R5 = 1.0, R6 = R7 = R8 = 8.0, and the ideal batteries have emfs script e1 = 8.0 V and script e2 = 4.0 V. The question asks to find the currents i1 and i2, and the energy rate of transfer in battery 1 and battery 2...

I would like a switch to seamlessly swap batteries between an experiment and a charger. Here is the description of the switch I am looking for. Originally I1 is connected to O1, I2 to O2 and so on. On turning the switch these things should happen in order: 1.) I3 and I4 are disconnected...

Hi all, If I take a battery (lets assume a car battery) and connect the +ve end to Earth Ground and leave the -ve end floating. Why is there no charge transfer from the battery to ground? I've read up on a variety of threads regarding this question on this forum. Haven't quite found my...

We have several Roombas in the house and we use a lot (12) of those little "invisible walls" to control where they can and can't go. They're all programmed to daily schedules, but even so, the invisible walls eat up a pair of C-cells every 60 days or so. 24 C-cells every couple of months gets...

I was just thinking about batteries and such after my brother asked me about AC vs DC current and their pros and cons.

are there batteries that recharge while they are in use? basically, the context is that i need a battery to be powering a control system all the time, but this battery will obviously drain. i wanted a solar recharger so there is no maintenance, but now I'm not even sure if this type of system...

We bought some rechargeable batteries a few years ago. However, we managed to lose the charger that went with it. :rolleyes: Now we bought some new rechargeable batteries with a new charger. This one is of a different brand. We still have the old batteries. My dad wants to use the new...

Hi, I am trying to test the validity of a simple lithium ion battery model that I consctructed to better understand the internal stress caused by the diffusion. I have referenced several papers and I am currently looking at how to calclualte the partial molar volume for a given material. To...

Hello there! Couple questions: 1. When a battery's terminals are connected by a copper wire, why is that called a circuit? Aren't the electrons moving, as a result of voltage difference, from the anion compartment of the battery to the cation compartment in a one-way direction? The fact...

electron/conventional theory - which way does electrons actually flow in a car battery? Ok, I'm confused about what I keep being told when I ask car mechanics about the jumpering of car batteries. I am hoping someone can help me with understanding which way electrons are actually going to...

Homework Statement Find the current through each component of the circuit. Homework Equations Kirchhoff's laws The Attempt at a Solution I labeled the current through the left battery I1 and the current through the right battery I2. Therefore the current through the resistor is...

Hi, I’ve recently come across brushless motors and their use in rc cars. The motor can supposedly bring a power of over 1000 Watts using for example NiMH batteries. BUT on those packs I read like say 2500mah, 12V , 5 AMPERE. Can an NiMH battery really release around a 150A current? If so can...

Homework Statement What are the main differences between between batteries in parallel vs. batteries in series? Homework Equations None The Attempt at a Solution I think batteries in parallel have the same voltage, while batteries in series' voltage adds up with how many batteries...

Is it dangerous to put, say, 100 D-cell batteries in series (the type you find in a flashlight)?

Hi, I am using a Wheatstone bridge to measure very low resistances (around 0,2ohms) and my measurements are changing from day to day. If I take the resistance measurement of the same resistor several times, I notice that each measurement will be lower than the next. But the next day, the...

in a simple circuit with only resistors and multiple batteries and multiple loops, which side is the positive and negative on the resistors? I am referring to the case of Kirchhoff rule in which I have to come up with equations to solve for current or voltage. But I got confused on voltage drop...

Hello all, this is my first post here and I am glad to be a new member of the PhysicsForums community! I have a question which I believe will be a good challenge for the bright minds here: I am trying to create a system of Al-Air batteries to power a motor which will be hooked up to an rc car...

. Homework Statement A ski resort consists of a few chair lifts and several interconnected runs on the side of the mountain with a lodge at the bottem. The lifts are analogous to the batteries and the runs are analogous to resistors. a) sketch how two runs can be in series b) sketch how two...

batteries or fuel cells? hydrogen costs too much to be an effective fuel alternative? the catalyst required for the electrochemical conversion reaction is pricey platinum? Using hydrocarbons as a source for hydrogen we have more CO2 in the atmosphere? and require a high temperature...

I have a bathroom scale which uses a 3v CR2016 battery. The battery only lasted about a month before needing to be changed. I thought that perhaps I was getting old batteries from stores, so I bought from a variety of stores and they all died quickly. My solution was to find the wires going...

Homework Statement The picture given to me was this one: Homework Equations I've been reading through the book but I don't really understand what I'm looking at. I know that V=I*R. I'm confused about the part between 1.5V and 2V--what does it mean that it's positive at both...

Will a batteries get discharged if the positive one is connected to the negative Hi,yestrday i was told when a wire is connected between two bodies being charged oppositely 'and equally in magnitude' then a sudden discharge take place making the bodies uncharged.So what about the charged...

Hi there, I need some help in getting this calculation done. I need to find out the number of batteries needed to power 5 devices of 12V for 18 hours. The voltage of the battery is also 12. Power of battery is 9600 watts. Please help. Thanks!

hi am going to do my mini project this feb...i have chosen this as my topic.. if anybody has information about this topic it may be of greater help...you can also give suggestion about some advanced technology in this particular field...

Why do batteries loose "omph" when it gets cold? Simple question really; It's well known that car batteries (and others) don't work as well when the temperature approaches -20C. I'm just wondering why? What's the physical reason? Also, if you bring the battery back to room temperature, will it...

Homework Statement Three identical batteries, with finite internal resistance, are connected in series in a closed loop. (Positive Terminal of battery 1 to Negative Terminal of battery 2; Positive Terminal of battery 2 to Negative Terminal of battery 3; Positive Terminal of battery 3 to...

I have 4 lead-acid batteries in parallel that I need to recharge. The batteries are Genesis NP7-12FR batteries rated at 12V, 7.0Ah. I need to create a circuit so that when I plug it into a 120VAC wall socket the batteries are charged. I was thinking of using a DC power supply but have no idea...

Homework Statement The circuit in the figure is composed of two batters (E1 = 5 V and E2 = 9 V) and four resistors (R1 = 110 W, R2 = 40 W, R3 = 50 W, and R4 = 50 W) as shown. Find I1 and I3 Homework Equations Well we need to apply KCL. I know the respective voltages (Ohm's law) need to...

I saw the following video: Lecture Series on Electronics For Analog Signal Processing I by Prof.K.Radhakrishna Rao, Department of Electrical Engineering,IIT Madras. For more details on NPTEL visit http://nptel.iitm.ac.in Category: Education Tags: Voltage Multiplier So I was wondering...

Hello everyone. I have a very simple problem here but I'm confused from the different concepts about the way charges or electrons flow inside the battery. Here's the question "Batteries always have two terminals, labeled + and -. The + terminal has the higher electric potential. If you...

Idea popped, and so I'm here. :) Can someone calculate maximal amperage and how long could an AA size mechanical battery (with spring inside) produce electricity at standard AA battery voltage (1.5V). ------------------------------------------- Description of that mechanical battery: -...

Homework Statement Hello everyone I need to find the current through the 22 ohm resistor. I've tried to solve this problem for many hours now... I can't find what I'm doing wrong! Please find a rough diagram attached. Homework Equations Kirchoffs rules The Attempt at a Solution...

Homework Statement Find the voltage between A and B in the circuit below: Homework Equations Don't know really, except for Ohm's law and Kirchhoff's laws, in some combination. 3. The Attempt at a Solution (rather the solution that the key gives, which I don't understand)...

How do these batteries work? Are they simply capacitors being connected in a parallel configuration? What is the difference between a laptop and a cell phone battery?

I understand that a battery works as a series of electrolytic cells when discharging, so would it be true than when it recharges, and undoes the electrolytic reactions, it acts as electrolysis reaction so that the anode can be replenished? Thanks in advance, would love some clarity on the issue.

Homework Statement The problems tells me to determine the potential difference between between two points. I alrady know that the potential of one point is zero. The problem I am having is that the cirucit has two batteries. I do not have a question so i will describe it, it hsould be easy...

Hi, Everyone! Is it possible to replace regular AA (or other) batteries with external DC power supplies (in general) or are there fundamental differences between these two sources of power? For example, my X-Box 360 joysticks (controllers) require two AA batteries each. I have Nokia power...

I have 3Kva UPS in which it has 6 12V 17Av batteries in it. which give me 10 minutes maximum backup on full load. What if i would like to increase the backup time, Can i additionally install car 12V 125Av battery with it? or additional battery bank with high Av batteries. Please can...

How does the amount of lead sulfate on the electrodes of a lead-acid battery affect its electric potential? The discharge reaction of a lead-acid battery produces amorphous lead (II) sulfate at the electrodes. If I can work out the number of moles of lead sulfate formed, how can I interpret...

Hi all, I'm doing this project entitled "determining the effects of Sulphation on lead-acid batteries", and what it essentially is, is the reason why these batteries lose their effectiveness after being left in a discharged state for a period of time. What happens is lead sulphate is formed...

Homework Statement two batteries are connected as shown, see attached 'drawing.' what is the terminal voltage across each batteryHomework Equations electric potential V = IR where I is current, R is resistance I = V_0/R * e^(-t/RC) where t is time, C is capacitance <--RC circuit...

Hey Everybody!...i have an Inquiry!... Can you run a motor of maximun 12000 RPM with batteries??... I mean...can you drive a DC motor of those speeds with batteries??...or perhaps can you do an adaptation so you can plug it to the AC line of the Alternator in the car so you can use the...

Why do automobile batteries have very low internal resistance?